The glycoproteinoses are among the most rare and least researched of the lysosomal diseases. The diseases include aspartylglucosaminuria, fucosidosis, galactosialidosis, alpha-mannosidosis, betamannosidosis, mucolipidosis II, mucolipidosis III, Schindler disease, and sialidosis. Longitudinal studies of these conditions are needed in order to better define the disease incidences, identify clinical features which could contribute to early diagnoses, detail progression of the diseases, assess efficacy of supportive therapies currently used, and identify potential treatments. The majority of published clinical information about these progressive, life-shortening conditions is in the form of isolated case reports. Establishing disease cohorts will allow recognition of features common to the disease spectrum or unique to subpopulations. Knowledge of disease course and establishment of genotype-phenotype correlations are fundamental to progress in testing and therapies. The project is designed to allow individuals affected with these rare diseases to contribute clinical information, including laboratory and imaging studies, obtained as part of their standard continuing medical care. Direct clinical evaluations will be performed by project personnel and repeated on a semi-annual basis when possible. Project personnel will collaborate with other clinical centers to provide assistance with clinical evaluations of patients.